Polyamide plasticized with urea for use in fusible compositions



United States Patent U.S. Cl. 26030.8 13 Claims ABSTRACT OF THE DISCLOSURE A fusible fabric is disclosed which comprises a fibrous web base having a solid fusible composition incorporated on at least one surface thereof. The fusible composition has a fusing point below 145 C. and comprises a polyamide and a plasticizing material containing urea, thiourea or ethyl urea.

This invention relates to fusible compositions and, in particular, to fusible compositions for incorporation into fibrous webs to form fusible fabrics and the like.

It is known to form fusible fabrics by incorporating discrete amounts of solid fusible compositions, for example, the thermoplastic materials polyethylene, cellulose acetate, or vinyl chloride copolymers, into at least the surface layers of woven or non-woven fabrics. Such fusible fabrics are very useful in the textile trade, for example, for imparting shape retention to conventional fabrics by lamination to the conventional fabrics under the influence of heat and pressure. Certain fusible fabrics may also be shaped into stiff articles of desired shape either alone or onlamination to conventional fabrics by the application of heat and pressure.

It is important that the fusible composition incorporated in the fusible fabric is substantially resistant to normal laundering processes and to dry cleaning fluids so that during laundering and/or dry-cleaning the tendency for laminated products formed from the fusible fabric to delaminate is at a minimum. It is also important that the fusible composition does not discolour or decompose under the fusing conditions and that the fusing temperature is such that the fibres of the fusible fabric or the fabric or other base material to which the fusible fabric may be laminated, are not scorched or otherwise discoloured. Preferably, the fusing temperature of the fusible composition should not exceed about 145 C. and more preferably should lie in the temperature range between about 95 C. and 130 C., which temperatures can conveniently be attained by conventional presses. Hitherto these desirable requirements have not all been found in fusible compositions of the prior art.

We have now found that alcohol-soluble linear polyamides are useful as improved fusible compositions when the fusing point of the polyamides has been lowered by incorporating in the polyamide a plasticising material comprising urea and/ or a urea derivative.

Accordingly, the present invention includes a fusible composition comprising at least one alcohol-soluble linear polyamide and a plasticising material in which the plas- 'ice ticising material comprises at least 20 parts by weight of urea and/ or a urea derivative for each parts by weight of polyamide with or without one or more further plasticisers for the polyamide, the plasticising material being present in such an amount that the fusing point of the fusible composition is below 145 C.

By alcohol-soluble linear polyamide is meant a linear polyamide capable of being dissolved in a lower aliphatic alcohol such as methyl or ethyl alcohol.

When the plasticising material comprises urea and/or a urea derivative as the sole plasticiser, the urea and/or urea derivative is preferably present in an amount not less than 100 parts by weight per 100 parts by weight of polyamide. More preferably, the amount of urea and/ or urea derivative is present in an amount between 150 and 250 parts by weight for each 100 parts by weight of polyamide. In general, the urea and/or urea derivative should not exceed about 400 parts by weight for each 100 parts by weight of polyamide.

When the plasticising material comprises urea and/or a urea derivative together with one or more further plasticisers, at least 20 parts by weight of the further plasticiser or plasticisers is preferably present per 100 parts by weight of polyamide. More preferably the amount of urea and/or urea derivative together with the further plasticiser or plasticisers should not exceed 150 parts by weight for each 100 parts by weight of polyamide and in the mixture of urea and/or urea derivative should not exceed about 125 parts by weight. Even more preferably, the plasticising material comprises between 50 and 100 parts by weight of urea and/or urea derivative and between 20 and 30 parts by weight of one or more of the further plasticisers for each 100 parts by weight of the polyamide.

Suitable urea derivatives which can be used in accordance with the invention are thiourea, ethyl urea and the like.

The further plasticisers suitable for use with the urea and/ or urea derivative are conveniently conventional polyamide plasticisers such as substituted benzene sulphonamides or 2 ethylhexyl p-hydroxybenzoate. A suitable substituted benzene sulphonamide for incorporating in the plasticising material is toluene sulphonamide and, in the practice of the invention, it is particularly convenient to use a mixture of ortho and para toluene sulphonamides marketed by Monsanto Chemical Company, London, England, under the name Santiciser 9.

The fusible compositions in accordance with the invention generally have a fusion point below 140 C. and more usually in the range of from C. to 130 C. and since, in addition, they have high adhesive properties in respect of fibrous materials, they are particularly useful in the manufacture of fusible fabrics.

When it is desirable that the fusing point of the fusible composition should be particularly low, for example, from about 100 C. to C. or lower, it is preferable to employ alcohol-soluble linear polyamides which are water-sensitive, that is, polyamides which are capable of absorbing Water and will soften in boiling water or under the influence of steam. Examples of suitable alcoholsoluble, water-sensitive linear polyamides are copolymers formed from the monomers of nylon 6 and nylon 66 in the ratio of monomer weights of between 70:30 and 40:60, and polyamide compositions marketed by Badische Anilin und Soda Fabrik A.G. of Ludwigshafen am Rhein,

Germany under the trade names Ultramid 1C and Ultramid 6A and mixtures of such compositions. Ultramid 1C is a mixed polyarnide in which the ratio of initial substances from which the polyarnide is produced is 33.3% adipic acid and hexamethylene-diamine, 33.3% caprolactam and 33.3% adipic acid and diaminodicyclohexylmethane. Ultramid 6A is a mixed polyamide produced from a combination of 66% adipic acid and hexamethylene-diamine and 33.3% caprolactam.

The present invention also includes fusible fabrics comprising fibrous webs incorporating a fusible composition in accordance with the invention upon at least one surface of the web.

The fibrous web may be a non-woven or bonded fibre fabric comprising textile fibres bonded together at points of contact with regenerated cellulose, natural or synthetic rubber or other material or a woven or knitted fabric. The fusible composition may be incorporated into at least the surface layer of the fibrous web in discrete portions by sprinkling as a powder followed by heating to fuse the particles to the fibres of the web, by spraying a solution of the fusible composition in a volatile solvent such as alcohol or an alcohol/water mixture on to the web followed by evaporation of the solvent or by printing a solution of the fusible composition on to the web in the form of dots, lines or other discontinuous pattern followed by evaporation of the solvent.

The fusible fabrics in accordance with the invention may readily be laminated to conventional fabrics by heat and pressure, suflicient to fuse the incorporated fusible compositions, to produce a laminate of high bond strength between the laminated parts, at a temperature readily attainable with conventional steam and dry presses which does not scorch or otherwise discolour the fabric.

A.G. of Ludwigshafen am Rhein, Germany, under the trade names Ultramid 1C and 6A were separately dissolved in the proportions shown in Table 1 in an-80z20 parts mixture of methyl alcohol and water to form aby weight solution of polyamides. To the separate solutions were added a mixture of ortho and para toluene sulphonamide marketed by Monsanto Chemicals Limited of London under the name Santicizer 9 and urea in the percentage proportions by weight shown in Table 1. The solutions were then sprayed on to one surface of a nonwoven fabric, formed of rayon and polyarnide fibres bonded by a synthetic rubber, in variousamounts to yield,- on evaporation of the solvent, discrete dry spots of fusible composition of various weights as shown in Table l. Strips 1 inch by 3 inches were cut from the surface treated fabrics and each strip was heat-sealed across its width to a 2 inch by 3 inch sample of the non-woven fabric which had not been surface treated with the fusible composition, by a heat-sealing apparatus in which the temperature of the heat-seal bar was varied as shown in Table 1 and the pressure applied was 5 pounds per square inch. No heat discolouration of the laminated fabrics was observed. The bond strengths of the laminates were measured by measuring the peel strength of the laminates by securing the free ends of the two strips forming each laminate to the jaws of a tensile testing machine and noting the force required to peel the strips apart. In certain cases the bond strength was greater than the strength of the fabric and delamination of the fabric occurred.

For the purpose of comparison of results, three extra experiments designated A, B, and C in Table 1, were carried out with urea or both of the plasticisers omitted.

Unsatisfactory peel strengths were obtained in each case.

TABLE 1 Weight of Dry Peel Polyamide, pts. by wt. Plasticisers, pts. by wt. Fnsible Temp. of Strength, Composn., Heat Seal gms./inch Example Ultramid 1C" Ultramid 6A Santictzer 9 Urea oz./sq. yd. Bar, C. strip 0. 8 130 1, 430(d) 0.75 120 880((1) 0. 8 140 1; 240(d) 0. 8 130 1, 360(d) 0. 6 140 660 0.8 130 190 0. 6 130 860 (d) indicates that the non-woven fabric delaminated.

EXAMPLE 8 Such lamination of the fusible fabric with the conventional fabric imparts shape retention to the conventional fabric and the method is particularly of use in the manufacture of stiffened articles of wearing apparel such as collars, shirts, cuffs, belts, skirts, and the like.

The bond strength of the laminate is not seriously weakened by normal laundry operations or conventional dry-cleaning fluids such as tetrachloroethylene to such an extent that delamination tends to occur.

The fusible fabrics in accordance with the invention may also be used for forming shaped articles, particularly articles of wearing apparel, when a blank of the fabric is shaped in a suitable formed die under heat and pressure, and the invention includes such a shaped article.

The fusible composition may, if required, be coated as a substantially continuous surface coating upon the fibrous web to form a heat-sealable fabric capable of being laminated to other fabrics or base material under the influence of heat and pressure, for example, for the purpose of repairing a rent in the fabric or base material.

The invention will now be further described by way of the following examples:

EXAMPLES 1 TO 7.

Alcohol-soluble, water-sensitive linear polyamides marketed by Messrs. Badische Anilin-und Soda Fabrik 25 parts by weight of powdered Ultramid 10 polyarnide resin was mixed with 25 parts of powdered Ultramid 6A polyarnide resin, 12.5 parts of Santicizer 9 toluene sulphonamide mixture and 37.5 parts of urea. The components of the mixture were melted together by heating slowly up to 150 C. and intimately mixed. After cooling, the melt was broken into granules which were then introduced with solid carbon dioxide into'a laboratory hammer mill'to form a powder. The powder'was then sprinkled on to one surface of a series of samples'of nonwoven fabrics of the same type as used in Examples 1 to 7 at rates'of 0.55 and 0.8 ounce per square yard. The particles'of powder on the fabric samples were fus'ed'in situ to the fabric by passing the samples through an air oven at 140 C. The resulting fusible fabric's'amples were cut into strips 3' inches by "1 inch and separately heatsealed across their width to woven rayon'and worsted cloths using respectively a Holfmann Steam Press at C. a dry plate press at C. and a hand electric iron at a surface temperature of 130 C.'No heat dis colouration of the laminated samples was observed. The laminated samples were tested for peel strength ina tensile testing machine as described in Examples Ito 7, when dry, when wet after shaking in tetrachloroethylene for" 5 minutes and when wet after boiling 'in a 1.0%

aqueous soap solution for five minutes. The results obtained are shown in Table 2.

and the mixer cover removed to permit free escape of water vapour.

TABLE 2 Feel Strengths (gins/inch strip) Weight of Powder Tetra per square yard of Woven chloro- Soap fabric (ounces/ Fabric ethylene Solution sq. yard) Type Press Dry Wet Wet Hofimann. 640 560(d) 100 Rayon Dry Plate... 600 520(d) 60 55 ron 520 510(d) O Hofimanm 720 620(d) 150 Worsted Dry Plate 690 640(d) 100 ron 600 520((1 50 Hofl-mann 1 250(d) 650(d) 250(d) Rayon Dry Plate"..- 1, 190((1) 600(d) 200 0 8 Iron ,060(d) 620(d) 200(d) Hoflmanm 1, 360(d) 00(d) 300(d) Worsted Dry Plate 1 220((1) 650((1) 200(d) Iron 1, 080(d) 620(d) 150 ((1) indicates that non-woven fabric delaminated.

From the results shown in Table 2, it is seen that there is some decline in peel strength when the laminated samples are tetrachloroethylene wet and more decline when the laminated samples are soap solution wet; however, these wet strengths were suificiently high to permit the laminated fabrics to be laundered or dry cleaned without any undue risk of delamination.

EXAMPLE 9 50 parts by weight of a powdered copolymer of 70% nylon 6 (condensation product of polycaprolactam) and 30% nylon 66 (condensation product of hexamethylene diamine and adipic acid) were introduced into a jacketed Pastorello mixer and 10 parts of water, 12.5 parts of Santicizer 9 and 37.5 parts of urea were separately added in that order. When all the ingredients had been added, steam was introduced into the jacket of the mixer and the contents were held at from 90 C. to 95 C. for 30 minutes before the cover was removed to allow free evaporation of the water. The resulting granules were ground to a powder which was then applied to one surface of a non-woven fabric of the same type as was used in Examples 1 to 7, at the rate of 0.75 ounce per square yard. The particles were fused in situ by passing the fabric briefly beneath an infra red heating unit. The fabric was cut into samples 3 inches by 1 inch and sealed under heat and pressure to a woven rayon and woven (worsted fabric, using the Hoffman press, a dry plate press and an electric iron as described in Example 8. The peel strengths obtained were about 90% the values obtained in Example 8, and the laminates withstood five commercial dry cleaning and five commercial laundry operations without any appreciable signs of delamination. Further, no scorch marks or discolouration were observed in the laminated samples.

EXAMPLE 10 The procedure described in Example 9 was repeated except that the polyamide component consisted of 50 parts by weight of a powdered copolymer of 40% nylon 6 and 60% nylon 66 and the mixer jacket was maintained at from 70% C. to 75 C. for 30 minutes by steam. The fusible fabric sample and the laminates formed therefrom had properties similar to the samples and laminates pre- 7 pared in Example 9.

EXAMPLE 11 100 parts by weight of a powdered copolymer of 70 nylon 6 and 30% nylon 66 was mixed in a Pfleiderer type mixer with 50 parts by weight of mixed N-ethyl derivatives of ortho and para sulphonamide with cooling water in the jacket of the mixer until a homogeneous dry powder was obtained. parts of water were then added and when evenly distributed, 75 parts of urea were added and the mixing continued. The temperature of the mixture was then raised to from 90-95 C. for minutes The fusible composition, and samples of fusible fabrics and laminates formed therefrom were found to have properties similar to the composition, samples and laminates prepared in Example 9.

EXAMPLE 12 A web of 3 denier nylon fibres of weight, 2 ounces per square yard, was needled by a needle punch machine at the rate of 3000 needles per square decimetre. The needled web was then sprayed with a 12% solution of equal quantities of Ultramid polyamide 1C and 6A in an /20 parts methyl alcohol/water mixture also containing 3% Santicizer 9 and 9% urea to give a dry weight of fusible composition of 0.8 ounce per square yard. The fusible composition bonded the fibres together to form a bonded fibre fabric. The fabric after drying was laminated to a knitted nylon lingerie material in a shaped steam press at C. to impart a cup-like shape to the laminated product. The laminate retained the cuplike shape and showed no sign of del'aminati on even after five commercial laundry operations.

EXAMPLE 13 The procedure as described in Example 9' was repeated except that 50 parts of urea were used in place of the mixed plasticiser of Santicizer 9 and urea, and the laminates were formed by sealing in a dry press at C. The results obtained were substantially the same as those obtained in Example 9 when using a dry press at a temperature of 130 C. No scorch marks or discolouration were observed.

EXAMPLE 14 The procedure described in Example '9 was repeated except that 37.5 parts of thioure a was used in place of the urea component of the mixed plasticiser. The results obtained on testing the laminate were substantially the same as those obtained in Example 9' and no scorch marks or discolouration were observed.

The word Santicizer is a registered trademark.

We claim:

1. A solid fusible composition having a fusing point below C. comprising at least one lower aliphatic alcohol-soluble linear polyamide and a plasticizing material in which the plasticizing material comprises between 20 parts and 400 parts by weight of at least one plasticizer selected from the group consisting of urea, thiourea, and ethyl urea for each 100 parts by weight of the polyamide.

2. A solid fusible composition as claimed in claim 1 in which the plasticizing material comprises between 100 and 400 parts by weight of at least one plasticizer selected from the group consisting of urea, thiourea, and ethyl urea as the sole plasticizer for each 100 parts by weight of the polyamide.

3. A solid fusible composition as claimed in claim 2 in which the plasticizing material comprises between and 250 parts by weight of at least one plasticizer selected from the group consisting of urea, thiourea, and ethyl urea as the sole plasticizer for each 100 parts by weight of the polyamide.

4. A solid fusible composition as claimed in claim 1 in which the plasticising material comprises at least 20 parts by weight of at least one further plasticiser for each 100 parts by weight of the polyamide.

5. A solid fusible composition as claimed in claim 4 in which the total weight of plasticizer in the plasticizing material does not exceed 150 parts by weight for each 100 parts by weight of polyamide and in which the plasticizer selected from the group consisting of urea, thiourea, and ethyl urea does not exceed 125 parts by weight.

6. A solid fusible composition as claimed in claim 5 in which the plasticizing material comprises between 50 and 100 parts by weight of a plasticizer selected from the group consisting of urea, thiourea, and ethyl urea and between and parts by weight of at least one further plasticizer for each 100 parts by weight of the polyamide.

7. A solid fusible composition as claimed in claim 6 in which the further plasticiser is a mixture of ortho and para toluene sulphonamide.

8. A solid fusible composition as claimed in claim 1 in which the lower alkyl alcohol-soluble linear polyamide is water-sensitive.

9. A solid fusible composition as claimed in claim 8 wherein said water sensitive lower alkyl alcohol-soluble linear polyamide is taken from the group consisting of copolymers formed from the monomers of nylon 6 and nylon 66 in the ratio of monomer weights between 7:30 and :60, a mixed polyamide formed from 33.3% adipic acid and hexamethylene-diamine, 33.3% caprolactam and 33.3% adipic acid and diaminodicyclohexylmethane and a mixed polyamide produced from 66.6% adipic acid and hexamethylene-diamine and 33.3% caprolactam.

10. A fusible fabric comprising a fibrous web taken from the group consisting of woven and non-woven fabric having a solid fusible composition incorporated on at least one surface thereof, said fusible composition having a fusing point below 145 C. and comprising at least one lower aliphatic alcohol-soluble linear polyamide and a plastic'izing material, said plasticizing material comprising between 20 parts and 400 parts by weight of at least one plasticizer selected from the group consisting of urea, thiourea, and ethyl urea for each parts by weight of the polyamide.

11. A fusible fabric as claimed in claim 10 in which the plasticizing material comprises between 100 and 400 parts by weight of at least one plasticizer selected from the group consisting of urea, thiourea, and ethyl urea as the sole plasticizer for each 100 parts by weight of polyamide.

12. A fusible fabric as claimed in claim 10 in which the plasticising material comprises at least 20 parts by weight of at least one further plasticiser for each 100 parts by Weight of polyamide.

13. A fusible fabric as claimed in claim 12 in which the total weight of plasticizers in the plasticizing material does not exceed 150 parts by weight for each 100 parts by weight of polyamide and in which the plasticizer selected from the group consisting of urea, thiourea, and ethyl urea does not exceed parts by weight.

References Cited UNITED STATES PATENTS 2,214,405 9/1940 Cofiman 260-308 2,610,927 9/1952 Foulds 260-308 2,913,448 11/1959 Tabler 260-324 3,321,433 5/1967 Baumann 260-32.4 3,100,721 8/1963 Holden 26032.6

ALLAN LIEBERMAN, Primaly Examiner.

P. R. MICHL, Assistant Examiner.

U.S. Cl. X.R. 

